joint polar satellite system 1 (jpss-1) spacecraft high...

December 11, 2014

Joint Polar Satellite System (JPSS) Program

Code 470

470-REF-00184

Joint Polar Satellite System 1 (JPSS-1)

Spacecraft High Rate Data (HRD) to

Direct Broadcast Stations (DBS)

Radio Frequency (RF)

Interface Control Document (ICD)

For Public Release

Check the JPSS MIS Server at https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the

correct version prior to use.

National Aeronautics and Space Administration

Goddard Space Flight Center

Greenbelt, Maryland

The information provided herein does not contain technical data as defined

in the International Traffic in Arms Regulations (ITAR) 22 CFC 120.10.

This document has been approved For Public Release to the NOAA

Comprehensive Large Array-data Stewardship System (CLASS).

https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm

472-00165

Effective Date: May 30, 2012

Revision -

Joint Polar Satellite System (JPSS) (Flight Project)

Code 472

472-00165

Joint Polar Satellite System 1 (JPSS-1)

Spacecraft High Rate Date (HRD) to

Direct Broadcast Stations (DBS)

Radio Frequency (RF)

Interface Control Document (ICD)

National Aeronautics and Space Administration

GSFC JPSS CMO

06/01/2012

Released


Greenbelt, Maryland

JPSS-1 HRD DBS RF ICD 472-00165


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Joint Polar Satellite System 1 (JPSS-1) Spacecraft

High Rate Data (HRD) to Direct Broadcast Stations (DBS)

Radio Frequency (RF) Interface Control Document (ICD)

JPSS Signature/Review/Approval Page

Prepared By:

Deane Charlson

Approved By:

Pam Sullivan

Electronic Approval available on-line at: https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm

--------------------------------------------------------------------------------------------------------------------


Greenbelt, Maryland

https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm



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Preface

This document is under JPSS Flight configuration control. Once this document is approved,

JPSS approved changes are handled in accordance with Class I and Class II change control

requirements as described in the JPSS Configuration Management Procedures, and changes to

this document shall be made by complete revision.

Any questions should be addressed to:

JPSS Configuration Management Office

NASA/GSFC

Code 472

Greenbelt, MD 20771



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Change History Log

Revision Effective Date Description of Changes

Rev - 05/30/2012 Initial Release. See CCR 472-CCR-12-0173.



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Table of TBDs/TBRs

Item No. Location Summary Individual/

Organization

Due Date



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Table of Contents

1. Introduction ............................................................................................................................ 1 1.1 Purpose.............................................................................................................................. 1 1.2 Interface Responsibilities ................................................................................................ 1 1.3 Interface Identification .................................................................................................... 1

1.3.1 RF Link Definition .................................................................................................... 1 1.3.2 Link Calculations ...................................................................................................... 1 1.3.3 Other RF Interfaces .................................................................................................. 1

2. Documents .............................................................................................................................. 3 2.1 Applicable Documents ..................................................................................................... 3 2.2 Reference Documents ...................................................................................................... 3 2.3 Other Related Documents ............................................................................................... 3

3. Communications Interface Requirements ........................................................................... 4 3.1 HRD Link Overview ........................................................................................................ 4

3.1.1 General ....................................................................................................................... 4 3.1.2 Interface RF Links .................................................................................................... 4

3.2 Interface Functional Requirements................................................................................ 4 3.2.1 General ....................................................................................................................... 4 3.2.2 Overview .................................................................................................................... 4 3.2.3 Mission Data .............................................................................................................. 4 3.2.4 Pseudo-Random Bit Stream (PRBS) ....................................................................... 5 3.2.5 Doppler Tracking and Ranging ............................................................................... 5

3.3 Communications Performance Characteristics ............................................................ 5 3.3.1 General ....................................................................................................................... 5 3.3.2 Mission Data Channel BER ..................................................................................... 5 3.3.3 PRBS Test Channel BER ......................................................................................... 5

3.4 Spacecraft/Direct Broadcast Station Communication Link (X-Band Downlink

Modes) ........................................................................................................................................ 5

4. HRD Link Interface Characteristics .................................................................................... 7 4.1 Purpose.............................................................................................................................. 7 4.2 Link Functional Designs: Spacecraft-to-Direct Broadcast Stations HRD Downlink 7

4.2.1 General ....................................................................................................................... 7 4.2.2 Functional Description ............................................................................................. 7

4.2.2.1 Data Formatting .................................................................................................. 9 4.2.2.2 Direct Broadcast User Ground Station Functionality ....................................... 9

4.3 Baseband Signal Characteristics .................................................................................. 11 4.3.1 General ..................................................................................................................... 11 4.3.2 Mission Data Baseband Signal Parameter ........................................................... 11 4.3.3 HRD Formatter ....................................................................................................... 11 4.3.4 HRD Randomizer.................................................................................................... 12 4.3.5 Data and Symbol Signal Formats .......................................................................... 12



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4.3.6 Convolutional Coding ............................................................................................. 13 4.4 RF Signal Characteristics.............................................................................................. 14

4.4.1 General ..................................................................................................................... 14 4.4.2 Signal Characteristics ............................................................................................. 14

4.4.2.1 DSN Protection ................................................................................................. 14 4.4.2.2 High Frequency Harmonic Protection ............................................................ 15 4.4.2.3 NTIA Bandwidth ............................................................................................... 16 4.4.2.4 Filter Characteristics ........................................................................................ 17 4.4.2.5 Doppler Shift ..................................................................................................... 17 4.4.2.6 Spurious Emissions ........................................................................................... 18

4.5 Ground Interface testing ............................................................................................... 18 4.5.1 HRD Compatibility Test......................................................................................... 18 4.5.2 End-to-End Test ...................................................................................................... 18

4.6 HRD Scheduling ............................................................................................................. 18

Appendix A RF Link Calculations ........................................................................................... 19

Appendix B Earth Coverage Antenna Patterns ...................................................................... 21

Appendix C HRD Spectrum ..................................................................................................... 23

Appendix D Acronyms and Abbreviations .............................................................................. 24

List of Figures

Figure 1-1. Spacecraft Communications Links ............................................................................. 2 Figure 4-1. Spacecraft-to-Direct Broadcast Station Downlink Configuration (Mission Data) ..... 8 Figure 4-2. Spacecraft-to-Direct Broadcast Station Downlink Configuration (PRBS Mode) ....... 8 Figure 4-3. HRD Randomizer Configuration .............................................................................. 12 Figure 4-4. HRD Randomizer Logic Diagram ............................................................................ 12 Figure 4-5. CCSDS Recommendation for Telemetry Channel Coding ....................................... 13 Figure 4-6. HRD Formatter/Transmitter Block Diagram ............................................................ 13 Figure 4-7. CCSDS HRD Formatting .......................................................................................... 14 Figure 4-8. HRD Harmonic Filter, Passband and Stopband response ......................................... 16 Figure 4-9. NTIA Bandwidth Requirement ................................................................................. 17 Figure 4-10. Doppler Shift Rate vs Elevation Angle ................................................................... 18 Figure A-1. Link Analysis at 5° Elevation Angle ........................................................................ 19 Figure A-2. Link Analysis vs User Terminal Elevation Angle ................................................... 20 Figure B-1. Single Sided Antenna Pattern Requirement as a Function of Offpoint Angle ......... 21 Figure B-2. Conical Cut (62° Offpoint Angle) Antenna Gain ..................................................... 22 Figure C-1. Spectral Plot.............................................................................................................. 23

List of Tables

Table 3-1. Spacecraft HRD Communication Modes ..................................................................... 6 Table 4-1. HRD Downlink Baseband and RF Signal Parameters vs Capability ........................... 9 Table 4-2. DSN Power Flux Density Analysis ............................................................................ 15



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1. Introduction

1.1 Purpose

This Interface Control Document (ICD) establishes performance requirements and defines and

controls technical aspects of the High Rate Data (HRD) communications subsystem interfaces

between the Joint Polar Satellite System-1 (JPSS-1) Spacecraft and Direct Broadcast Users

worldwide within line-of-sight view. The HRD provides real-time mission data (which includes

instrument science data, instrument engineering data, and instrument telemetry data), and real-

time Spacecraft housekeeping data via X-Band downlink transmission.

1.2 Interface Responsibilities

Ball Aerospace and Technologies Corporation (BATC), under contract to Goddard Space Flight

Center (GSFC) JPSS-1 Project Office, is responsible for the JPSS-1 Spacecraft portion of the

interface. Users of the Direct Broadcast Stations are responsible for meeting the requirements

laid out in this ICD. Design requirements and parameters in this ICD are controlled by the GSFC

JPSS-1 Project Office Change Control Board (CCB), with inputs from GSFC JPSS-1 Project

Personnel, Raytheon, and BATC as appropriate.

1.3 Interface Identification

1.3.1 RF Link Definition

The communications subsystem interface defined and controlled by this ICD is the HRD Radio

Frequency (RF) transmission link between the JPSS-1 Spacecraft and the Direct Broadcast Users

as defined in Section 3. This ICD does not apply to the RF links of any other spacecraft/vehicle,

tracking system, or dedicated ground terminal. Figure 1-1 depicts the RF links between the

Spacecraft and its various interfaces.

1.3.2 Link Calculations

The RF link calculations contained in Appendix A for the Spacecraft modes of operation are

included only as supporting data and do not constitute a formal part of the RF ICD agreement.

The Earth-coverage antenna patterns and downlink spectrum provided in Appendix B and

Appendix C, respectively, are included for information purposes and are also not part of this RF

ICD agreement.

1.3.3 Other RF Interfaces

The RF interfaces between the JPSS-1 Spacecraft and the Space Network (SN), the JPSS-1

Spacecraft and the S-Band Ground Stations, and the JPSS-1 Spacecraft and the Ka-Band Ground

Stations are included in separate RF ICDs. This ICD provides the definition of the HRD links

between the JPSS-1 Spacecraft and the X-Band Direct Broadcast Users.



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Figure 1-1. Spacecraft Communications Links



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2. Documents

2.1 Applicable Documents

The following documents are applicable to the JPSS-1 Spacecraft.

GSFC 472-00009 JPSS-1 Satellite Requirements Specification

National Telecommunications and Information Administration (NTIA), Manual of

Regulations and Procedures for Federal Radio Frequency Management (Redbook)

2.2 Reference Documents

The following documents are reference documents applicable to the RF interface being

controlled. These documents do not form a part of this ICD and are not controlled by their

reference herein.

CCSDS 131.0-B-2 Consultative Committee for Space Data Systems (CCSDS)

Recommendations for TM Synchronization and Channel Coding


Recommendations for Advanced Orbiting Systems – Networks and

Data Links: Architectural Specification


Recommendations for Advanced Orbiting Systems (AOS) Space Data

Link Protocol

GSFC 429-01-02-19 IRD for NPP Mission System to Direct Broadcast Users Interface

ITU-R SA 1157 Protection Criteria for Deep-Space Research

2.3 Other Related Documents

The following documents are listed for the convenience of the user. These documents do not

form a part of this ICD and are not controlled by their reference herein.

BATC 2348495 Procurement Control Drawing, HRD Transmitter (HRDTx), JPSS-1

BATC 2378912 JPSS-1, Telecom Subsystem Design Description SER

BATC 2373580 Command and Telemetry Handbook, JPSS-1 Program

BATC 3549479 Mission Data Format Control Book



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3. Communications Interface Requirements

3.1 HRD Link Overview

3.1.1 General

The Spacecraft will use an Earth-coverage pattern antenna to provide downlink for Direct

Broadcast Users. It provides real-time mission data (which includes instrument science data,

instrument engineering data, and instrument telemetry data), and real-time Spacecraft

housekeeping data. The data rate is 15 Mbps at a nominal downlink frequency of 7812 MHz. In

normal operations broadcast data will operate continuously providing real-time data to the Direct

Broadcast Users.

3.1.2 Interface RF Links

The required RF communication links are as follows:

a. Mission data from Spacecraft-to-Direct Broadcast Users

b. Pseudo Random Bit Stream (PRBS) for Bit Error Rate (BER) measurements

3.2 Interface Functional Requirements

3.2.1 General

Paragraphs 3.2.2 to 3.2.5 describe the X-Band interface functional requirements that exist

between the Spacecraft and the Direct Broadcast Users.

3.2.2 Overview

The HRD system hardware onboard the Spacecraft consists of two transmitters, one transfer

switch, and one shaped reflector antenna. The antenna is designed to give Earth-coverage

radiation pattern. Antenna patterns are shown in Appendix B for reference. The system is

designed to always be on, with the ability to be turned off indefinitely. Figure 4-6 shows the

architecture for the HRD system and the interface to the Mission Data Formatter (MDF). The

Direct Broadcast User Terminal demodulates and decodes the RF received from the Spacecraft

communication subsystem. The Spacecraft to Earth station link distance ranges from 2835 Km

at a ground station elevation angle of 5°, to 824 Km at a ground station elevation angle of 90°.

Direct Broadcast Station support is dependent on favorable radio line-of-sight conditions when

Direct Broadcast Station antenna elevation angle is greater than 5° (above the local horizon).

3.2.3 Mission Data

Transmission of real-time payload data from the Spacecraft to Direct Broadcast Users of HRD

occurs at 15 Mbps. Mission data will be formatted in accordance with Spacecraft requirements

outlined in paragraph 4.3. The 15 Mbps is the Channel Access Data Unit (CADU) bit rate,

measured after Reed-Solomon coding and pre-pending the Attached Sync Marker. After rate 1/2

convolutional coding is applied, the in-phase (I)- and quadrature-phase (Q)-channels are each

Quadrature Phase Shift Key (QPSK) modulated with 15 Msps (30 Msps total). Data from the



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HRD is selectable by Application Identification (APID) via table load. In all cases, fill frames

are added in order to maintain the 15 Mbps downlink rate.

3.2.4 Pseudo-Random Bit Stream (PRBS)

The satellite will generate pseudo-random bit stream test data as a test mode used for the purpose

of BER checking, as required. It is not a normal X-Band spacecraft operation. The satellite shall

reset upon command back to the default configuration from the pseudo-random output.

NOTE:

The link analysis for the PRBS is not shown since the Mission Data link analysis is worst case.

3.2.5 Doppler Tracking and Ranging

The Direct Broadcast Stations must be able to handle a maximum Doppler shift of ± 171.0 kHz

at an elevation angle of 5°, and a Doppler shift rate of 1.55 kHz/sec at an elevation angle of 90°.

This link does not provide a ranging capability.

3.3 Communications Performance Characteristics

3.3.1 General

RF link performance requirements for the communications functional capability described in

paragraph 3.2 are defined in this section. Direct Broadcast Station communications performance

requirements are based on the presumption that the Spacecraft and Direct Broadcast Station each

perform in accordance with the system performance parameters defined in Section 4.

3.3.2 Mission Data Channel BER

The maximum HRD downlink information BER for the mission data channel will be 1.83x10-3,

referenced to the input of a Reed Solomon (RS) Decoder on the ground. With RS decoding at

the Direct Broadcast terminal, the effective output mission data BER will be 10-8. The HRD

Interface Requirements Document (IRD) requires an Eb/No of 4.4 dB, which is more stringent

than the 10-8 BER requirement. Therefore the link analysis is performed using the Eb/No

requirement of 4.4 dB.

3.3.3 PRBS Test Channel BER

The maximum HRD downlink information BER for the PRBS test channel will be 1x10-4,

referenced to the output of the Viterbi decoder on the ground per the HRD IRD. Actual

performance will be better than 10-5 based on the Eb/No requirement of 4.4 dB.

3.4 Spacecraft/Direct Broadcast Station Communication Link (X-Band Downlink

Modes)

The Spacecraft X-Band downlink modes are shown in Table 3-1.



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Table 3-1. Spacecraft HRD Communication Modes

Service Data Mode

Rate

(Mbps)

Antenna

(Polarization) Modulation

I:Q Power

Ratio

Direct

Broadcast

Users

HRD

(mission data)

15 Earth-coverage

antenna

(RHCP)

QPSK 1:1

Direct

Broadcast

Users

PRBS 15 Earth-coverage

antenna

(RHCP)

QPSK 1:1



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4. HRD Link Interface Characteristics

4.1 Purpose

This section specifies the functional design of the RF HRD link. Pertinent Spacecraft and Direct

Broadcast Station communications signal designs and system performance requirements are also

specified.

4.2 Link Functional Designs: Spacecraft-to-Direct Broadcast Stations HRD Downlink

4.2.1 General

The HRD transmitter will be used to transmit the data for this link. Baseband characteristics will

be in accordance with Table 4-1. The Earth-coverage antenna provides 15 Mbps data to the

Direct Broadcast Users. The HRD system is designed to transmit data at all times, however, it

can be turned off indefinitely if the need arises.

4.2.2 Functional Description

The functional interface of the Mission Data link will be as shown in Figure 4-1, and the

functional interface of the PRBS test bit stream link will be as shown in Figure 4-2.

a. Spacecraft mission data or PRBS data are sent from the MDF board within the Command

and Data Processor (CDP) to the HRD transmitters. The signal from the CDP is Low

Voltage Differential Signal (LVDS) in a Non-return to Zero Level (NRZ-L) format.

b. The data are then converted from NRZ-L to Non-return to Zero Mark (NRZ-M) format

and is then convolutionally encoded.

c. The convolutional encoder outputs are split with G1 on the I-channel and G2 (inverted)

on the Q-channel. The I-channel and Q-channel data is QPSK modulated onto the X-

Band carrier with an I/Q-channel power ratio of 1:1 as shown in Figure 4-1 and Figure 4-

2. The X-Band carrier is derived from a Temperature Compensated Crystal Oscillator

(TCXO).

d. These data streams QPSK modulate onto a 7812 MHz carrier. The resulting Transmitter

RF output is amplified to 7 watts minimum, over full specified unit temperature range, 8

watts minimum at maximum flight allowable temperature range. The link uses the Earth-

coverage antenna to transmit to Direct Broadcast Users.



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Figure 4-1. Spacecraft-to-Direct Broadcast Station Downlink Configuration (Mission

Data)

Figure 4-2. Spacecraft-to-Direct Broadcast Station Downlink Configuration (PRBS Mode)



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4.2.2.1 Data Formatting

Data formatting for Mission Data is as follows (see Figure 4-1):

a. CCSDS format into coded Advanced Orbiting Systems (AOS) Transfer Frames (TF),

(formerly referred to as Coded Virtual Channel Data Units (CVCDU’s)) with Reed

Solomon (RS) (255,223), I=4

b. Randomize coded AOS transfer frames (see Section 4.3.4)

c. CCSDS format into Channel Access Data Units (CADU’s) by adding sync (see Section

4.3.4)

d. Differential encode

e. Convolutional encode (as described in paragraph 4.3.6)—the G1 output will be routed to

the I channel, and the G2 (inverted) output will be routed to the Q channel of the HRD

transmitter.

Data formatting for PRBS mode is as follows (see Figure 4-2):

a. All zeroes input

b. Randomize the input by using the following bit transition generation function (refer to

CCSDS 131.0-B-2 Recommendations for TM Synchronization and Channel Coding,

Section 9):

h(x) = x8 + x7 + x5 + x3 +1

c. Differential encode

d. Convolutional encode (as described in paragraph 4.3.6)—the G1 output will be routed to

the I channel, and the G2 (inverted) output will be routed to the Q channel of the HRD

transmitter.

When operating in the PRBS mode, the CADU sync pattern is disabled. See also Figure 4-6.

Details of data formatting are further covered in the JPSS-1 HRD Data Format ICD.

4.2.2.2 Direct Broadcast User Ground Station Functionality

At the Direct Broadcast Users Receive Ground Station, the input signal from the receive antenna

is down converted before being input to the QPSK receiver/demodulator. The QPSK

receiver/demodulator demodulates the down converted signal into separate I and Q channel data

streams with NRZ-M format. Following QPSK demodulation, the bit synchronizers recover

symbol clock, the data are Viterbi decoded, and converted to NRZ-L format. After conversion to

NRZ-L the data will be de-randomized. Table 4-1 contains minimum performance requirements

for the Direct Broadcast capability of the spacecraft and the Users Ground Stations.

Table 4-1. HRD Downlink Baseband and RF Signal Parameters vs Capability

Parameter Requirement Capability Comply

Transmit Center Frequency

7812 0.03 MHz 7812 0.03MHz Yes

Data Rate 15,000,000 bps +/- 6 Kbps 15,000,000 bps +/- 6 Kbps

Yes

Polarization RHCP RHCP Yes



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Axial Ratio Ground

Elevation Angle (deg)

Angle from Spacecraft Antenna

Boresight (deg)

Axial Ratio (dB)


Boresight (deg)

Axial Ratio (dB)

NA

5 40 70 90

61.9 42.7 17.6

0

None 61.9 42.7 17.6

0

6.0

Coverage 62 62 (1) Yes

Minimum EIRP (dBm) Ground

Elevation Angle (deg)


Boresight (deg) EIRP (dBm)


Boresight (deg) EIRP (dBm)

5 40 70 90

61.9 0.1

42.7 0.1

17.6 0.1

0 0.1

42.8 33.6 30.8 30.3

61.9 0.1

42.7 0.1

17.6 0.1

0 0.1

43.1 35.2 33.6 31.2

Yes

Data Modulation QPSK Compliance Yes

Data Format, Modulator Output

NRZ-M output Compliance Yes

Assigned Bandwidth (-20 dB)

30 MHz 30 MHz Yes

Gain Slope over fc 15 MHz

0.2 dB/MHz Angle from Spacecraft Antenna

Boresight (deg) Gain Slope

61.9 43.6 17.9

0

0.001 0.001 0.001 0.001

Yes

Gain Flatness over fc 15MHz

2.0 dB p-p

2.0 dB p-p

Yes

Phase Non-linearity over fc

15 MHz 6 degrees p-p

6 degrees p-p

Yes

I/Q Power Ratio (Nominal) 1:1 1:1 Yes

I/Q Power Ratio Tolerance 0. 5 dB 0. 5 dB Yes

QPSK Phase Imbalance 4.5 4.5 Yes

QPSK Gain Imbalance 1 dB p-p 1 dB p-p Yes

Data Asymmetry 3% 3% Yes

Data Bit Jitter 1% 1% Yes

Phase Noise (Offset from Carrier) 100 Hz – 40 MHz Spurious Phase Modulation

2.0 degrees RMS

2.0 degrees RMS

2.0 degrees RMS

2.0 degrees RMS

Yes

AM/PM 10°/dB <10°/dB Yes

I/Q Data Skew < 5% of bit period < 5% of bit period Yes

Operational Duty Cycle, Science Mode

100% 100% Yes

Service Interruption HRD shall have the ability to be turned ON or OFF

HRD can be commanded ON or OFF

Yes

Frequency Stability Over all conditions

1x10-5

1x10-5

Yes

HRD System BER 1x10-8 (link margin 1 dB) 1x10-8 Yes

Untracked Spurious PM (100 Hz to 40 MHz)

2 2 Yes

Carrier Suppression ≤ -30 dBc -30 dBc Yes

Spurious Emissions (out-of-band)

≤ -60 dBc -60 dBc Yes



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4.3 Baseband Signal Characteristics

4.3.1 General

This paragraph provides a description of the baseband signal characteristics of the HRD

downlink signal to the Direct Broadcast Users. The formatting process is illustrated in Figure 4-

7.

4.3.2 Mission Data Baseband Signal Parameter

The Spacecraft HRD downlink baseband signal parameters for the mission data are contained in

Table 4-1, along with the modulation and RF signal parameters.

4.3.3 HRD Formatter

The MDF within the CDP shall provide a HRD Formatter function that allows CCSDS CADUs

to be generated from CCSDS AOS transfer frames provided by the CDP flight software (FSW).

The HRD Formatter shall apply Reed-Solomon coding to create Coded AOS transfer frames.

The Reed Solomon code used shall be standard CCSDS 255,223 with interleave depth 4 as

defined in CCSDS 131.0-B-2, Section 4. The addition of Reed-Solomon coding to the incoming

AOS transfer frames was previously defined as CCSDS Grade 2 telemetry service (historically

defined in CCSDS 701.0-B-3, Paragraphs 2.3.3 and 2.4.1.2.f) but this terminology is no longer

used in the recommendations. A block diagram of the HRD Formatter and transmitter is shown

in Figure 4-6. Fill frames with Virtual Channel 63 are added as necessary at the AOS transfer

frame level in order to maintain a constant 15 Mbps formatted downlink rate as shown in the

diagram. In order to perform BER tests, an all 0’s input may be switched into the system prior to

the randomizer as shown in Figure 4-6. Additionally, the PRN stream has the CADU Sync

Marker turned off.

Ground Station Pointing Loss

1 dB 1 dB Yes

Ground Station Implementation Loss

2.5 dB 2.5 dB Yes

Ground Station Multipath

Loss at 5 Elevation angle 0.2 dB 0.2 dB Yes

Ground Station G/T (dB/K) 3 meter antenna Reference: IRD for NPP Mission System to Direct Broadcast Users Interface

Ground Elevation G/T (dB/K) (2)

Ground Elevation

G/T (dB/K) (2)

Yes

5

40

70

90

22.7 23.59 23.65 23.66

5

40

70

90

22.7 23.59 23.65 23.66

NOTE 1. Allows for +/-0.3 degree pointing uncertainty 2. The link availability is dependent upon actual location of the User Terminal. Reference the Link Analysis in

Appendix A.



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4.3.4 HRD Randomizer

The HRD Formatter shall provide a function to randomize telemetry data contained in AOS

transfer frames. The randomization process shall be Enable/Disable selectable by command.

The data shall be randomized in compliance with CCSDS 131.0-B-2, Section 9, when the HRD

data randomizer is enabled. The HRD Randomizer configuration is illustrated in Figure 4-3. The

Logic for the HRD data randomizer is shown in Figure 4-4. The data shall bypass this process

when the HRD data randomizer is disabled. The 32-bit synchronization marker is added to each

Data Unit in order to complete the CADU format.

Coded AOS TF

from Data Stream

Pseudo-Random

Sequence Generator

En/Ds Command

Sync Pattern

Generator

CADU

Process

Data Output(CCSDS CADU)

Figure 4-3. HRD Randomizer Configuration

X8

X7

X6

X5

X4

X3

X2

X1

Initialize to an "all ones" state for each Coded AOS TF

during the period when the Sync Pattern is selected.

=Modulo-2 adder

(Exclusive-OR)

=Single Bit Delay

Pseudo-random

sequence

DATA OUT(Randomized Coded AOS TF)

DATA IN(Coded AOS TF)

Figure 4-4. HRD Randomizer Logic Diagram

4.3.5 Data and Symbol Signal Formats

After randomization and insertion of the frame synchronization marker, the signal is serially

converted from NRZ-L to NRZ-M.



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4.3.6 Convolutional Coding

The Spacecraft will encode the HRD stream with a rate ½, constraint length 7 convolutional

coding as defined in CCSDS 131.0-B-2, Section 3. Figure 4-5 shows the encoder block diagram.

The convolutional encoder outputs are routed with G1 to the I channel and G2 (inverted) to the Q

channel of the modulator.

D

=Modulo-2 adder

(Exclusive-OR)= Single Bit Delay

D D D D D

G2

= Inverter

Outputs from the

convolutional encoder

map to the I and Q

inputs of the QPSK

Modulator

INPUT DATA

STREAM

G1

D

Q

I

Figure 4-5. CCSDS Recommendation for Telemetry Channel Coding

MDF-2 HRDTx-2MDF-1

Input Buffer

(AOS TFs

From

CDP FSW)

Extract AOS TF

and perform

AOS TF

Header Check

Generate

CCSDS

Coded AOS TFs

(add RS Coding)

PRN Gen/

Randomizer

Randomize

Enable/Disable Cmd

Generate

CCSDS

CADUs

(ASM)

LVDS

Fill (VC63)

Clear Cmd

0

Test Mode

Enable/Disable Cmd

HRDTx-1

Input MUX

A/B input select

NRZ-L to

NRZ-MRate 1/2, K=7

Convo Encode

QPSK

Modulater

X-Band

Synth

SSPA

Input A

Q

IG1

G2G2

G1

Input B

COLD SPAREREDUNDANT

CONNECTION

PRIMARY

UNIT

Figure 4-6. HRD Formatter/Transmitter Block Diagram



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Multiplexing

Protocol Data Unit(ref: CCSDS 732.0-B-2,

Fig. 4-3)

M_PDU Header

Spare

(00000)

First Header

Pointer

5 bits 11 bits

2 Octets

M_PDU Packet Zone

End of previous

CCSDS packet #kCCSDS packet #k+1 CCSDS packet #m Start of CCSDS packet #m+1

884 Octets

Version-1 CCSDS

Space Packet(ref: CCSDS 133.0-B-1,

Fig. 4-1 & Fig 4-2)

AOS Transfer Frame(ref: CCSDS 732.0-B-2,

Fig. 4-2)

Version

No.

(01)

MASTER CHANNEL ID

Spacecraft

ID

(10011101)

Virtual

Channel ID

(0 - 63)

2 bits 8 bits 6 bits

2 Octets

Signalling Field

Replay

Flag

(1)

Spare

(0000000)

1 bit 7 bits

1 Octet

Virtual Channel

Frame Count

(0 - 16,777,215)

3 Octets

M_PDU

886 Octets

Forward Error Correction

Code R-S (255, 223)

(Interleave Depth 4)

128 Octets

Attached Sync

Marker

(ASM)

(0x1ACFFC1D)

4 Octets

TRANSFER FRAME (UNCODED)

892 Octets

Channel Access

Data Unit(ref: CCSDS 131.0-B-2)

TRANSMITTED CODEBLOCK

(normally Randomized)

TRANSFER FRAME PRIMARY HEADER TRANSFER FRAME DATA FIELD

Version

No.

(000)

Packet ID

Type

Indicator

(0)

Sec Hdr

Flag

(0 or 1)

APID

(0 - 2047)

3 bits 1 bit 1 bit 11 bits

2 Octets

Packet Sequence Control

Sequence Flags

01 = first packet

00 = cont. packet

10 = last packet

11 = no grouping

Packet

Sequence

Count

(0 - 16383)

2 bits 14 bits

2 Octets

Packet

Data

Length

(0 - 65535)

2 Octets

PACKET PRIMARY HEADER PACKET DATA FIELD

Source Data

1 - 65536 Octets

Microseconds

of Milliseconds

0 to 999

Secondary Header = T-Field

Day(Epoch = 1/1/00)

0 to 65535

Milliseconds of Day

0 to 86,399,999

2 Octets

8 Octets

4 Octets2 Octets

Figure 4-7. CCSDS HRD Formatting

4.4 RF Signal Characteristics

4.4.1 General

For the Spacecraft-to-Direct Broadcast Users HRD 15 Mbps downlink, balanced QPSK

modulation (channel power ratio of 1:1) is used.

4.4.2 Signal Characteristics

The signal characteristics of the HRD downlink are in accordance with Table 4-1. QPSK

modulation is employed. The X-Band carrier is modulated by the I and Q baseband signals. The

HRD downlink uses an Earth-coverage antenna on the Spacecraft.

4.4.2.1 DSN Protection

Deep Space Network (DSN) interference criteria of, –255.1 dBW/m2 Hz from 8400 to 8450

MHz, is met by filtering the HRD transmitter appropriately in this band.

Table 4-2 shows the DSN power Flux Density Analysis.



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Table 4-2. DSN Power Flux Density Analysis

Parameter Power Units Reference

HRDTx Po 14.0 watts Max Spec Power

Power in dBW 11.46 dBW

Passive Loss -2.0 dB Lowest case loss

Ant Gain

(worst case peak)

9.5 dBi Worst case antenna gain

(SC not nadir pointed)

EIRP 18.96 dBW (sum of above)

RF vs. unmodulated -71.8 dB

(Sin X)/X loss -41.9 dB Peak 8400 to 8450 MHz

Filter Loss -56 dB Tx Filter at 39th sideband

Spectral re-growth

(estimate)

10 dB amplifier in some compression

Spreading factor -129.3 dB 824 Km distance

(S/C directly over DSN)

Total -270.04 dBW/m2 per Hz

Requirement -255.1 dBW/m2 per Hz SA 1157 8400 to 8450 MHz

Margin 14.94 dB Worst Case

4.4.2.2 High Frequency Harmonic Protection

A post HRD transmitter output X-Band Bandpass filter will be employed to best comply with the

protection of payload electronics. The passband and stopband filtering characteristics are shown

in Figure 4-8.



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Figure 4-8. HRD Harmonic Filter, Passband and Stopband response

4.4.2.3 NTIA Bandwidth

The filtering of the HRD downlink will be within the NTIA bandwidth mask as shown in Figure 4-9.



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Figure 4-9. NTIA Bandwidth Requirement

4.4.2.4 Filter Characteristics

A pre-final amplifier filter is employed to meet the requirement of 4.4.2.1 and 4.4.2.2. The filter

characteristic is shown in Figure 4-9. The spectral output is shown in Appendix C.

4.4.2.5 Doppler Shift

The Spacecraft will be traveling at a velocity of ~7.44 Km/sec at an altitude of 824 Km, this

results in a maximum Doppler shift of ±171.0 kHz at an elevation angle of 5°. Figure 4-10

shows the Doppler shift rate as the Spacecraft travels over the different elevation angles. The

max rate of change of 1.55 kHz/sec occurs at an elevation angle of 90°.



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Figure 4-10. Doppler Shift Rate vs Elevation Angle

4.4.2.6 Spurious Emissions

All out-of-band spurious emissions will be less than –60 dBc.

4.5 Ground Interface testing

4.5.1 HRD Compatibility Test

The JPSS-1 Spacecraft will be made available to perform HRD compatibility testing for the

purpose of verifying compatibility with the specified HRD ground station. A hard-line RF

output from the transmitter and an air link path will be available for this compatibility testing.

4.5.2 End-to-End Test

For End-to-End (ETE) testing during JPSS-1 Compatibility Tests (JCTs), a hardline RF output

with the HRD signal will be made available for use with the ground receiver and processor

located in the Satellite factory clean room. The RF signal will have the characteristics described

above in sections 4.1 through 4.4.

4.6 HRD Scheduling

Data regarding JPSS-1 scheduling, ephemeris information, predicted outages, and other user

messages will be stored on the Mission Support Data Server (MSDS). Authorized Direct

Broadcast Users may retrieve mission support data via the internet. The MSDS Uniform

Resource Locator (URL) will be provided to the Direct Broadcast User upon registration with the

JPSS-1 Program.



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Appendix A RF Link Calculations

Figure A-1 summarizes the worst case HRD link margin with a 5o elevation angle. Figure A-2

has been included to show the link margins over various elevation angles.

Figure A-1. Link Analysis at 5° Elevation Angle



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HRD Margin vs. Elevation Angle

0

1

2

3

4

5

6

7

8

9

10

11

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

Elevation Angle (Degrees)

Ma

rgin

(d

B)

HRD Link Margin

1 dB Margin

Figure A-2. Link Analysis vs User Terminal Elevation Angle



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Appendix B Earth Coverage Antenna Patterns

Figure B-1 shows the Earth Coverage HRD antenna pattern as a function of the offpoint angle.

Contained within these plots is the RHCP antenna gain (blue), LHCP antenna gain (green) and

the necessary antenna gain to maintain a 1 dB HRD link margin (red). As shown in this figure

the Earth Coverage antenna maintains the necessary link margin over all angles. Figure B-2 has

been included to demonstrate a conical cut of the antenna gain at the 62o offpoint angle.

Figure B-1. Single Sided Antenna Pattern Requirement as a Function of Offpoint Angle



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Figure B-2. Conical Cut (62° Offpoint Angle) Antenna Gain



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23

Appendix C HRD Spectrum

Figure C-1. Spectral Plot



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24

Appendix D Acronyms and Abbreviations

AM Amplitude Modulation

AOS Advanced Orbiting Systems

APID Application Identification

BATC Ball Aerospace and Technology Corporation

BER Bit Error Rate

bps bits per seconds

C Celsius

CADU Channel Access Data Unit

CCB Change Control Board

CCSDS Consultative Committee for Space Data Systems

CDP Command and Data Processor

CMD Command

CVCDU Coded Virtual Channel Data Unit

dB Decibel

dBc Decibel/carrier

dBi Decibel Isotropic

dB/K Decibel/Kelvin

dBm Decibel/miliwatt

DBS Direct Broadcast Stations

dBW Decibel/Watt

deg degrees

Ds Disable

DSN Deep Space Network

EIRP Effective Isotropic Radiated Power

En Enable

ETE End-to-End

FSW Flight Software

GHz Giga Hertz

GSFC Goddard Space Flight Center

G/T Gain-to-Noise Temperature Ratio

HRD High Rate Data

HRDTx High Rate Data Transmitter

Hz Hertz

I In-phase

ICD Interface Control Document

IRD Interface Requirements Document

JCT JPSS Compatibility Tests

JPSS-1 Joint Polar Satellite System-1

K Kelvin

Kbps Kilo bits per second

Km Kilometer

LVDS Low Voltage Differential Signal



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Mbps Mega bits per second

MDF Mission Data Formatter

MHz Mega Hertz

MSDS Mission Support Data Server

Msps Mega symbols per second

NASA National Aeronautics and Space Administration

NPOES National Polar-Orbiting Operational Environmental Satellite System

NPP NPOESS Preparatory Project

NRZ Non Return to Zero

NRZ-L Non Return to Zero-Level

NRZ-M Non Return to Zero-Mark

NTIA National Telecommunications and Information Administration

PCM Pulse Code Modulation

PM Phase Modulation

PO Program Office

p-p peak-peak

PRBS Pseudo-Random Bit Stream

PRN Pseudo-Random Noise

Q Quadrature

QPSK Quadrature Phase Shift Key

RF Radio Frequency

RFICD Radio Frequency Interface Control Document

RHCP Right Hand Circular Polarization

RMS Root Mean Square

RS Reed Solomon

S/C Spacecraft

sec second

SER System Engineering Report

SN Space Network

SNUG Space Network Users’ Guide

SSPA Solid State Power Amplifier

synch synchronizer

TBD To Be Determined

TBR To Be Reviewed

TCXO Temperature Compensated Crystal Oscillator

TDRS Tracking and Data Relay Satellite

TDRSS Tracking and Data Relay Satellite System

TF Transfer Frame

TLM Telemetry

URL Uniform Resource Locator

VCDU Virtual Channel Data Unit